Natural flaky graphite in Shandong, China was purified by H2O2, a new patent method to produce graphite without sulfur and used as precursor to prepare exfoliated graphite through microwave irradiated expansion with some chemicals (such as hydrogen peroxide, nitric acid, and acetic acid). With the centrifugation process, graphene was synthesized by using an efficient and simple method under ultrasonic and microwave irradiation at the room temperature. Natural graphite and exfoliated graphite were characterized by X-ray diffraction and scanning electronic microscopy, and the resultant graphene was investigated and confirmed by atomic force microscopy, Raman micro-spectrometer, etc. Natural graphite in Shandong, China, consisted of mainly hexagonal (2H) and a little rhombohedral structure (3R), was beneficial for the synthesis of graphene. Graphene-like nanosheets about 1 to 3 nm, around three to five carbon layers can be synthesized efficiently by microwave and ultrasonic irradiation with natural graphite.
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